WO2020211625A1

WO2020211625A1 - Display device and display method therefor

Info

Publication number: WO2020211625A1
Application number: PCT/CN2020/082048
Authority: WO
Inventors: 孟宪芹; 王维; 梁蓬霞; 李忠孝; 陈小川; 孟宪东; 田依杉
Original assignee: 京东方科技集团股份有限公司
Priority date: 2019-04-17
Filing date: 2020-03-30
Publication date: 2020-10-22
Also published as: CN109856854A

Abstract

A display device and a display method therefor. The display device comprises: an upper substrate (101) and a lower substrate (102) which are arranged opposite each other; a liquid crystal layer (103) and a driving electrode (104) which are located between the upper substrate (101) and the lower substrate (102), the refractive index of the liquid crystal layer (103) being controlled to change between a maximum refractive index (ne) and a minimum refractive index (no) in a birefringence of the liquid crystal layer (103) by loading a driving voltage on the driving electrode (104); a waveguide layer (105) located between the liquid crystal layer (103) and the upper substrate (101); and a collimating light source (106) located on the side face of the waveguide layer (105).

Description

Display device and display method thereof

Cross references to related applications

The embodiments of the present disclosure require the rights and interests of the Chinese patent application with application number 201910310207.1 filed with the Chinese Patent Office on April 17, 2019, and the entire content of the application is incorporated herein by reference.

Technical field

The present disclosure relates to the field of display technology, and more particularly to a display device and a display method thereof.

Background technique

Since the development of displays, there have been several important research and development directions, such as energy-saving display, ultra-high definition, ultra-wide color gamut and color purity display, ultra-large and ultra-thin display, three-dimensional display and so on. The expectation is to restore the most real colors to the display screen as losslessly as possible, maximize the use of ambient light, and minimize power consumption. Among them, the demand for ultra-high PPI is one of the problems that the display will focus on in the future. The rapid development of VR/AR display now promotes the rapid development in this direction.

Therefore, how to reduce the process difficulty while ensuring PPI is an urgent problem to be solved.

Summary of the invention

In order to at least partially overcome the defects and/or deficiencies in the above-mentioned related technologies, embodiments of the present disclosure provide a display device and a display method thereof.

The embodiments of the present disclosure provide technical solutions as follows:

According to the first aspect of the embodiments of the present disclosure, an embodiment of the present invention provides a display device, including:

The upper substrate and the lower substrate arranged oppositely;

The liquid crystal layer and the driving electrode located between the upper substrate and the lower substrate, by applying a driving voltage on the driving electrode, the refractive index of the liquid crystal layer is controlled to be the maximum refractive index among the birefringence of the liquid crystal layer And the minimum refractive index change;

A waveguide layer located between the liquid crystal layer and the upper substrate; and

A collimated light source located on the side of the waveguide layer.

In an exemplary embodiment of the present disclosure, the driving electrode adopts a conductive grating structure in which positively charged electrodes and negatively charged electrodes are alternately arranged in a lateral direction perpendicular to the normal direction of the display device.

In an exemplary embodiment of the present disclosure, the driving electrode is a transparent conductive material.

In the exemplary embodiment of the present disclosure, it further includes:

Brightness sensor, the brightness sensor is located at the opposite side edges of the display device, and is configured to detect the brightness of the ambient light, and adjust the brightness of the collimated light source according to the detected brightness of the ambient light.

In an exemplary embodiment of the present disclosure, the upper substrate is located on the light-exit side of the display device, and when the waveguide layer and the upper substrate are different layers adjacent to each other, the upper substrate Located on the surface of the waveguide layer facing away from the lower substrate.

In an exemplary embodiment of the present disclosure, the upper substrate is located on the light exit side of the display device, and, in the case where the waveguide layer is multiplexed with the upper substrate, the upper substrate is located on the liquid crystal layer. On the surface facing away from the lower substrate.

In the exemplary embodiment of the present disclosure, it further includes:

A cladding layer located on a surface of the upper substrate facing away from the liquid crystal layer, and the refractive index of the cladding layer is lower than the refractive index of the upper substrate.

In an exemplary embodiment of the present disclosure, the coating layer is formed of a transparent material.

In an exemplary embodiment of the present disclosure, at least one of the upper substrate and the lower substrate is formed of a transparent material.

In an exemplary embodiment of the present disclosure, the liquid crystal layer is a liquid crystal layer operating in an ADS mode.

According to the second aspect of the embodiments of the present disclosure, the embodiments of the present disclosure also provide a display method applied to the above-mentioned display device, including:

Scanning the pixels in the display device line by line;

When scanning a row of pixels, an electric field is applied to the liquid crystal layer of the row of pixels according to the gray value of each pixel, so that the refractive index of the liquid crystal layer of the pixel is the maximum refractive index and the minimum refractive index in the birefringence of the liquid crystal layer Rate varies between.

Description of the drawings

By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the embodiments of the present disclosure will become more apparent. In order to explain the technical solutions of the embodiments of the present disclosure more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative labor, other drawings can be obtained based on these drawings. The above-mentioned and/or additional aspects and advantages of the embodiments of the present disclosure are combined with the drawings below. The description of the embodiments will become obvious and easy to understand, where:

FIG. 1 is a schematic structural diagram of a display device provided by an embodiment of the disclosure;

FIG. 2 is a state diagram of the display device when the driving electrode is loaded with a driving voltage;

FIG. 3 is an implementation flowchart of a display method applied to the display device according to an embodiment of the present invention.

detailed description

The embodiments of the present disclosure will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described here are only used to explain the related invention, but not to limit the invention. In addition, it should be noted that, for ease of description, only the parts related to the invention are shown in the drawings. For the sake of clarity, the various parts in the drawings are not drawn to scale. In addition, some well-known parts may not be shown in the figure.

In the following, many specific details of the embodiments of the present disclosure are described, such as the structure, materials, dimensions, processing technology and technology of the components, in order to understand the embodiments of the present disclosure more clearly. However, as those skilled in the art can understand, the embodiments of the present disclosure may not be implemented according to these specific details.

The size and shape of the components in the drawings do not reflect the true proportions of the components of a display device of the embodiments of the present disclosure, and the purpose is only to schematically illustrate the content of the embodiments of the present disclosure.

It should be noted that the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other if there is no conflict.

According to the general technical idea of the embodiment of the present disclosure, in one aspect of the embodiment of the present disclosure, a display device is provided. As shown in FIG. 1, it is a schematic structural diagram of a display device provided by an embodiment of the present disclosure. The display device includes:

The upper substrate 101 and the lower substrate 102 are arranged oppositely;

The liquid crystal layer 103 and the driving electrode 104 located between the upper substrate 101 and the lower substrate 102, by applying a driving voltage on the driving electrode 104, control the refractive index of the liquid crystal layer 103 in the birefringence of the liquid crystal layer, the maximum refractive index ne and Change between minimum refractive index no;

The waveguide layer 105 located between the liquid crystal layer 103 and the upper substrate 101;

The collimated light source 106 located on the side of the waveguide layer 105.

Among them, the maximum refractive index ne and the minimum refractive index no are the extraordinary refractive index and the ordinary refractive index in the birefringence of the liquid crystal layer, respectively.

The upper substrate 101 and/or the lower substrate 102 are, for example, formed of a transparent material, such as a higher refractive index LCD (Liquid Crystal Display) or OLED (Organic Light-Emitting Diode, organic light-emitting diode) substrate glass. Alternatively, for example, some special optical glass or resin materials are used, but not limited thereto. The thickness is, for example, 0.1-2mm. The specific thickness is determined by product design or process conditions, and the upper and lower surfaces are required to have good flatness and parallelism.

The collimated light source 106 is, for example, an edge-type collimated light source, such as but not limited to CCFL (Cold Cathode Fluorescent Lamp), B (LED) + Y phosphor, RG phosphor, and QD (quantum dot) The light source is also alternatively, for example, a highly collimated light source, or alternatively, for example, a divergent light source. The light incident from the collimated light source 106 is concentrated and incident on the waveguide layer 105.

The light emitted by the collimated light source 106 is formed by mixing the three monochromatic lights of R, G, and B to form white light, or white light can be formed by white LED light strips with relatively good collimation, or alternatively by strips CCFL tubes add some light collimating structures to form white light, but it is not limited to these types. In order to match the width of the panel, for example, a laser chip or LED light bar with the same width as the panel is used, or some beam expansion structures are added in front of a sparsely distributed laser chip or LED light bar. For example, the light exit direction of the collimated light source 106 needs to form a certain angle with the normal of the waveguide layer 105, so that the incident light can be totally reflected at the interface between the waveguide and the upper substrate. When aligned with the waveguide layer, the side collimated light source 106 is arranged to cover the side of the waveguide layer 105, but does not directly emit light to the liquid crystal layer and the layers above. In the actual structure, there will be a sealant on the outermost surface of the liquid crystal layer, and no light will enter the liquid crystal layer.

The liquid crystal material of the liquid crystal layer 103 is, for example, a positive liquid crystal, and then the liquid crystal layer 103 is a liquid crystal layer working in an ADS mode. Among them, the ADS mode is the abbreviation of ADSDS (Advanced Super Dimension Switch, Advanced Super Dimension Switch Technology). It is a general term for the core technology represented by wide viewing angle technology. It uses materials that are formed on the same array substrate, such as ITO materials. The formed pixel electrode and the common electrode generate the lateral electric field (especially the fringe electric field between the two) to deflect the liquid crystal molecules to realize the image display mode, which essentially belongs to the improved category of the IPS mode.

It should be noted that the drawings of the present disclosure only schematically show that two kinds of electrodes with different electric properties are alternately arranged (for example, to serve as a pixel electrode and a common electrode), but in fact, in a more specific embodiment For example, the two electrodes with different electrical properties are arranged in the same layer as shown schematically in the drawings (in this case, it is substantially equivalent to the IPS mode of the related technology, and the electric field between the two is only parallel. The Ey electric field in the lateral direction of the array substrate, thereby driving the horizontal rotation of the liquid crystal molecules to generate gray scales for display); or in an alternative more specific embodiment, for example, a HADS equivalent to the ADS mode is used , IADS, or AADS are three specific working modes of electrode settings. More specifically, the two electrodes with different electrical properties are not located in the same layer, but more specifically, at least one insulating layer is formed between them , And the two overlap at least partially, and the overlapping part of the two (that is, the part where the respective orthographic projections of the two overlap each other on the array substrate) constitute the storage capacitor of the corresponding pixel to maintain the liquid crystal molecules during one frame time In this case, the electric field between the two includes not only the transverse electric field Ey parallel to the transverse direction of the array substrate, but also the stronger perpendicular to the array distributed near the edges of the two electrodes. The vertical electric field Ez in the normal direction of the substrate can increase the degree of deflection of the liquid crystal molecules in the on state, and achieve better and effective light transmission at the edge of the electrode, increase the pixel aperture ratio, and improve The transmittance of the entire panel. In other words, a fringe electric field is formed between the two kinds of electrodes, and the liquid crystal molecules are driven to rotate horizontally via the fringe electric field to generate gray scales for display.

In the embodiment of the present disclosure, the thickness of the liquid crystal layer 103 is generally about 3um.

The driving electrode 104 is, for example, formed on the surface of the lower substrate 102 facing the liquid crystal layer 103, and is covered by the liquid crystal layer 103 (essentially it can be regarded as the driving electrode 104 is placed in the liquid crystal layer 103, and one side is from the liquid crystal layer 103). 103 is exposed to abut the lower substrate 102), and for example, positively charged electrodes and negatively charged electrodes are alternately arranged in a lateral direction perpendicular to the normal direction of the display device to form a conductive grating structure, and the alternating arrangement period of the electrodes is determined by The designed light emission direction and color are determined. The duty cycle is usually set to 0.5, for example, and the height of the grating is usually set to about 200 nm, for example, and the specific value depends on the beam confinement capability of the waveguide layer 105.

The driving electrode 104 is, for example, a transparent conductive material, such as ITO (Indium Tin Oxide), or, for example, a metal, such as Mo (molybdenum) or Ag (silver), or Al (aluminum). For example, the thickness is suitably selected to meet the requirements of the applied voltage, such as 70-300 nm. In some embodiments of the present disclosure, for example, a transparent conductive material is selected.

The waveguide layer 105 is, for example, transparent, and a material with a higher refractive index is usually selected to form a waveguide to effectively confine light waves. Specifically, the refractive index of the waveguide layer 105 is, for example, higher than the refractive index of the material of the upper substrate 101, for example, it is selected to be made of materials such as ITO or Si ₃ N ₄ ; and the thickness is, for example, 2 μm or even thicker to several tens of microns, But it is not limited to this. Controlling the change of the refractive index of the liquid crystal layer can make the light out of the waveguide layer into the liquid crystal layer.

In addition, the display device in the embodiment of the present disclosure may additionally include a brightness sensor, which may be located on opposite sides of the display device. The brightness sensor is configured to detect the brightness of the ambient light and adjust the collimation by the detected brightness of the ambient light. The brightness of the light source 106. The brightness sensor is selected as a photoresistor, for example.

In an exemplary embodiment of the present disclosure, the upper substrate 101 is located on the light exit side of the display device. More specifically, in the case where the waveguide layer 105 and the upper substrate 101 are different layers adjacent to each other, the upper substrate 101 is located on the surface of the waveguide layer 105 that faces away from the lower substrate 102; and In the case where the waveguide layer 105 is multiplexed with, for example, the upper substrate 101, the upper substrate 101 is located on the surface of the liquid crystal layer 103 that faces away from the lower substrate 102.

In an exemplary embodiment of the present disclosure, the display device may additionally include, for example, a cladding layer 107 on the surface of the upper substrate 101 facing away from the liquid crystal layer 103. The refractive index of the cladding layer 107 should be lower than that of the upper substrate. 101’s refractive index. The coating layer 107 is also formed of, for example, a transparent material, such as optical glass or resin material.

In addition, a frame sealant 108 that encloses the liquid crystal layer is provided on the periphery of the liquid crystal layer 103, and the frame sealant 108 encloses the liquid crystal layer 103 in the lateral direction.

Referring to FIG. 1, it is a case where the driving electrode 104 is not loaded with a driving voltage, and this is the initial state of the display device. When all the film materials are formed of transparent materials, the ambient light can directly pass through the display device, and the display device is in a transparent state. At this time, the display device is equivalent to glass and does not affect the viewing of the screen behind the display device.

Referring to FIG. 2, it is a case where the driving electrode 104 is loaded with a driving voltage. At this time, the display device is switched to a reflection state in which light of a specific wavelength is filtered. Assuming that under the condition of no ambient light, the collimated light source 106 is turned on, and the driving electrode 104 is applied with a driving voltage. At this time, a liquid crystal grating is formed in the liquid crystal layer 103. The extending direction of the bars of the formed liquid crystal grating is, for example, parallel to the extending direction of the strip-shaped electrodes.

In order to ensure that the liquid crystal layer 103 can realize the small-sized grating through the large-sized driving electrode, the liquid crystal simulation software TechWiz is used in the embodiment of the present disclosure to simulate the deflection state and dynamic response of the liquid crystal layer 103 under the above-mentioned design of the driving electrode 104 In the process, the final study determined that in the design of the driving electrode 104 in the embodiment of the present disclosure, the period of forming the liquid crystal grating is one-half of the period of the driving electrode 104. For example, Figure 2 shows one of these two periods. Relationship between.

As far as the current processing technology is concerned, the smaller the grating structure is, the more difficult it is to process, especially when the periodic parameters drop to the nanometer level, the greater the processing difficulty and the worse the control accuracy. Such an ADS liquid crystal material and a liquid crystal grating formed by driving electrodes with a positive and negative alternating grating structure, for example, are formed with a period of half the electrode period, which greatly reduces the difficulty of the process and regulates the direction and intensity of light. This type of liquid crystal drive mode is used for other display modes and liquid crystal gratings, for example.

Based on the above display device, an embodiment of the present disclosure also provides a display method applied to the display device, including the steps shown in FIG. 3:

Step 31: Scan the pixels in the display device line by line.

Step 32: When scanning a row of pixels, apply an electric field to the portion of the liquid crystal layer corresponding to the row of pixels according to the gray value of each pixel, so that the refractive index of the liquid crystal layer corresponding to the pixel is between ne and no Change between.

The "correspondence" here means, for example, that the orthographic projection of a certain pixel on the lower substrate 102 and the orthographic projection of the corresponding part of the liquid crystal layer on the lower substrate 102 at least partially overlap, or even completely overlap, so that the driving electrode faces the liquid crystal layer. The application of an electric field to the corresponding part results in the grayscale required for imaging of the pixel.

In the embodiments of the present disclosure, as the refractive index of the liquid crystal layer of the pixel changes, the display effect of the display device also changes accordingly.

Among them, the display effects of the display device are mainly divided into two types: transparent display and reflective display.

Transparent display is a state that does not need to be displayed, that is, the driving electrode 104 is not loaded with a driving voltage, and the collimated light source 106 is not lit. The display device is equivalent to glass and does not affect the viewing of the picture behind the display device.

Reflective color display, that is, the driving electrode 104 is loaded with a driving voltage, and the liquid crystal layer 103 forms a liquid crystal grating. Here, "reflective color display" means that the liquid crystal grating is selective to the light of different wavelengths projected on it. At different parts of the liquid crystal grating, the light of the corresponding specific wavelength is diffracted and passed, and the light of other wavelengths is reflected back to realize the light of the specific wavelength is diffracted by the liquid crystal grating to display the corresponding color light, but not The finger light is reflected by the human eye toward the observer to realize the display. Specifically, the selection of different wavelengths of light distributed at each part of the grating is specifically embodied as: the period, height, and duty cycle of the liquid crystal grating at each part are correspondingly designed by the color of the light to be emitted. It is determined that certain geometric parameters can allow certain specific wavelengths to pass, while other wavelengths cannot pass and are directly reflected back, so as to achieve specific colors of light. It should be pointed out that when different driving voltages are applied to the electrodes in different parts, the height of the corresponding parts of the formed liquid crystal grating will change accordingly, which affects the light emission.

Specifically, the settings for achieving selective light emission of different wavelengths (ie, colors) at different parts of the grating are as follows, for example.

The realization of red light emission: As an example, when the geometric parameters of the liquid crystal grating at the part where red is expected to be realized are designed as: the formed grating strip period is, for example, 330-450nm (especially 350nm), and the width is 190-210nm (especially In the case of 198nm), red light in the range of 600-780nm is obtained.

The realization of green light emission: As an example, when the geometric parameters of the liquid crystal grating at the part where green is expected to be realized are designed as follows: the formed grating strip period is, for example, 240-280nm (especially 240nm), and the width is 125-145nm (especially In the case of 135nm), the green light emission in the range of 500-600nm is obtained.

The realization of blue light: As an example, when the geometric parameters of the liquid crystal grating at the part where blue is expected to be realized are designed as follows: the formed grating has a period of 120-200nm (especially 180nm), and a width of 90-110nm ( Especially in the case of 102nm), the blue light emission in the range of 380-500nm is obtained.

Utilizing the structure size parameter setting of each part of the grating as above, it is convenient to realize the light emission of R, G, and B pixels.

And in an additional embodiment, for example, it is possible to realize complementary colors of cyan (C) and yellow (Y), combine the existing RGB three primary colors to realize RGBCY five primary color display, expand the color gamut, and achieve high saturation and high color Domain display. The specific explanation is as follows.

The realization of cyan light emission: As an example, when the geometric parameters of the liquid crystal grating at the place where cyan is expected to be realized are designed as follows: the formed grating strip period is, for example, 210-230nm (especially 220nm) and the width is 110-130nm (especially In the case of 124nm), the cyan light emission in the range of 450-550nm is obtained.

The realization of yellow light emission: As an example, when the geometric parameters of the liquid crystal grating at the part where yellow is expected to be realized are designed as: the formed grating strip period is, for example, 290-320nm (especially 300nm), and the width is 160-180nm (especially In the case of 170nm), a yellow light emission in the range of 580+/-50nm is obtained.

In a more specific embodiment, the "reflective color display" includes the following three implementation forms when different ambient light is incident from the back:

1. When the ambient light is strong enough, the display mode is directly realized through the ambient light. In this mode, the collimated light source 106 is not lit, and the ambient light directly projected from the back is used as the backlight, and the ambient light is reflected and filtered by the liquid crystal grating to realize the liquid crystal color display with ambient light as the light source.

2. When the ambient light is very weak, the side-mounted collimated light source 106 lights up, is incident obliquely into the waveguide layer and is reflected, and the color is developed through the liquid crystal grating to realize the liquid crystal color display with the collimated light source as the light source.

3. When the intensity of the ambient light is between the above two states, there is the ambient light directly projected from the back and the side incident light from the collimated light source 106 obliquely incident into the waveguide layer 105 and reflected side light in the panel. In this case, for example, an ambient light intensity detection sensor, such as a dynamic iris, can sense the ambient light intensity signal in real time and transmit it back to the system light intensity signal. According to the user's brightness design, the light source 106 can be collimated to different degrees. Based on the driving of light intensity, it is actually provided to adjust the collimated light source according to the ambient light intensity detected in real time to realize the compensated light emission, thereby realizing a display mode in which the image quality is not affected by the ambient light intensity.

In the liquid crystal color display, the driving voltage applied to the driving electrode 104 is different, and the refractive index of the liquid crystal layer 103 also changes accordingly. When the refractive index of the liquid crystal layer 103 is less than the refractive index of the waveguide layer 105, total reflection is achieved in the waveguide layer 105, resulting in no light coupling out of the waveguide layer 105, and it is in the L0 state; when the refractive index of the liquid crystal layer 103 is greater than When the refractive index of the waveguide layer 105 and the difference between the refractive index of the liquid crystal layer 103 and the grating refractive index are the largest, the effect of the liquid crystal grating is the most obvious, and the coupling efficiency of light coupling out of the waveguide layer 105 is the highest, which is in the L255 state; when the liquid crystal layer 103 When the refractive index is between the above two conditions, it is in other grayscale states. For example, when different driving voltages are applied, the height of the formed liquid crystal grating is inconsistent, which realizes the control of the light intensity and thus realizes the control of the color display pixel The further grayscale control.

When realizing color display, the diffraction grating formula can be used:

n _i sinθ _i -n _d sinθ _d = mλ/Λ(m=1, 2, 3...)

Where ni and

They are the refractive index and the incident angle of the medium through which the light enters the diffraction grating, m is the diffraction order, Λ is the grating period, λ is the wavelength of the incident light, and θd is the clamp between the direction of the diffracted light and the plane normal Angle, nd is the refractive index of the liquid crystal layer, the equivalent refractive index of the driving electrode and the upper substrate (generally the refractive indices of the three are also very close). The light-emitting direction of a pixel at a certain position on the panel is often fixed, which is determined by the position of the pixel relative to the human eye, that is, the light-emitting direction θd of the display mode in the above formula is fixed. Considering this situation, by setting the period Λ of the grating at different positions for the light emission direction θd, as described above, light of a given color (wavelength λ) can be emitted in a given direction θd.

Compared with related technologies, based on the above technical solutions, the display device and display method provided by the embodiments of the present disclosure have at least the following superior technical effects:

The display device provided by the embodiment of the present invention includes an upper substrate and a lower substrate that are arranged oppositely; a liquid crystal layer and a driving electrode located between the upper substrate and the lower substrate are controlled by applying a driving voltage on the driving electrode The refractive index of the liquid crystal layer varies between a maximum refractive index ne and a minimum refractive index no; a waveguide layer located between the liquid crystal layer and the upper substrate; a collimated light source located on the side of the waveguide layer. Compared with related technologies, the process difficulty can be greatly reduced under the condition of ensuring PPI.

The above description is only a preferred embodiment of the embodiments of the present disclosure and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover the above-mentioned technical solutions without departing from the inventive concept. Other technical solutions formed by any combination of technical features or equivalent features. For example, the above-mentioned features and the technical features disclosed in the embodiments of the present disclosure (but not limited to) having similar functions are replaced with each other to form a technical solution.

Claims

A display device, characterized by comprising:

The upper substrate and the lower substrate arranged oppositely;

The liquid crystal layer and the driving electrode located between the upper substrate and the lower substrate, by applying a driving voltage on the driving electrode, the refractive index of the liquid crystal layer is controlled to be the maximum refractive index among the birefringence of the liquid crystal layer And the minimum refractive index change;

A waveguide layer located between the liquid crystal layer and the upper substrate; and

A collimated light source located on the side of the waveguide layer.
The display device according to claim 1, wherein the driving electrode adopts a conductive grating structure in which positively charged electrodes and negatively charged electrodes are alternately arranged in a horizontal direction perpendicular to the normal direction of the display device.
3. The display device of claim 2, wherein the driving electrode is made of a transparent conductive material.
The display device of claim 1, further comprising:

Brightness sensor, the brightness sensor is located at the opposite side edges of the display device, and is configured to detect the brightness of the ambient light, and adjust the brightness of the collimated light source according to the detected brightness of the ambient light.
The display device according to claim 1, wherein the upper substrate is located on the light-exit side of the display device, and, when the waveguide layer and the upper substrate are different layers adjacent to each other, The upper substrate is located on the surface of the waveguide layer facing away from the lower substrate.
The display device of claim 1, wherein the upper substrate is located on the light-emitting side of the display device, and when the waveguide layer is multiplexed with the upper substrate, the upper substrate is located On the surface of the liquid crystal layer facing away from the lower substrate.
The display device of claim 1, further comprising:

A cladding layer located on a surface of the upper substrate facing away from the liquid crystal layer, and the refractive index of the cladding layer is lower than the refractive index of the upper substrate.
8. The display device of claim 7, wherein the coating layer is formed of a transparent material.
The display device according to claim 1, wherein at least one of the upper substrate and the lower substrate is formed of a transparent material.
3. The display device of claim 1, wherein the liquid crystal layer is a liquid crystal layer working in an ADS mode.
A display method applied to the display device according to any one of claims 1-10, characterized in that it comprises:

Scanning the pixels in the display device line by line;

When scanning a row of pixels, an electric field is applied to the liquid crystal layer of the row of pixels according to the gray value of each pixel, so that the refractive index of the liquid crystal layer of the pixel is the maximum refractive index and the minimum refractive index in the birefringence of the liquid crystal layer Rate varies between.